OpenPGP

OpenPGP is the most widely used email encryption standard. It is defined by the OpenPGP Working Group of the Internet Engineering Task Force (IETF) as a Proposed Standard in RFC 4880. OpenPGP was originally derived from the PGP software, created by Phil Zimmermann.

Email encryption

Although OpenPGP’s main purpose is end-to-end encrypted email communication, it is also utilized for encrypted messaging and other use cases such as password managers.